Russian Foreign Minister Sergey Lavrov Friday said Japan's “excessively emotional” reaction to the dispute over the Kuril Islands has further strained relations and stalled regional development. He made the remarks ahead of his departure on an official visit to Tokyo, during which he is scheduled to meet his counterpart Koichiro Genba Saturday, the Interfax news agency reported. Japan and Russia have long disagreed over the status of four of the Pacific island chain's most southern islands, which Tokyo claims as part of its northern province Hokkaido but Moscow has controlled since the end of World War II. “If there has been a cooling in Russian-Japanese relations, then it certainly is not our fault,” Lavrov said. “One should look for the cause in excessively emotional reactions by some Japanese political groups to visits by Russian officials to the South Kuril Islands,” he said. Two meetings between Russian President Dmitry Medvedev and Japanese leaders in 2011 failed to defuse the historical dispute, which has now threatens to overshadow work on improving economic ties and political cooperation in the Pacific arena, Lavrov said. Development of its Far Eastern provinces is a top priority for Russian and Japanese business could play a critical role in the region's fishing, energy and tourism industries, Lavrov said. Visits by both Medvedev and Prime Minister Vladimir Putin to Russian military bases on the island Kunashir in recent years have been closely watched in Russia and Japan.